Introduction

In this article, I am describing what is Window Communication Foundation (WCF) and why it is introduced in .NET Framework 3.0.

Background

In Modern Application (Distributed Application) development, you can use COM+, .NET Enterprise Services, MSMQ, .NET Remoting, Web services, etc. for communication. All these technologies play a different role and to use it you need to develop different solutions for different technologies. You have to focus on each of the technologies to develop rather than the application business logic.

WCF unifies the capabilities into single, common, general service oriented programming model for Communication. WCF provides a common approach using a common API which developers can focus on their application rather than on communication protocol.

Why Do We Need WCF?

There is one main Bank system which is directly connected with the database, that provides other systems like ATM machine, Loan System data using various communication protocols like Remoting, web service, etc. For communicating with different Systems using different communication protocols, you have to know the API of that technology. In WCF, you have to just make different End points for different services. There is no need to learn a different API. You can use only one common API for communication with different System.

In WCF, you have to just make different End points for different services. There is no need to learn a different API. You can use only one common API for communication with a different System.

WCF Architecture

ABC of an EndPoint in WCF

All communications with the WCF service will happen via the endpoints. The endpoints specify a Contract that defines which methods of the Service class that will be accessible via the endpoint; each endpoint may expose a different set of methods. The endpoints also define a binding that specifies how a client will communicate with the service and the address where the endpoint is hosted.

A-Address(Where?): Specifies the location of the service which will be like http://Myserver/MyService.Clients will use this location to communicate with our service.

B-Binding-Address(How?): Specifies how the two parties will communicate in terms of transport and encoding and protocols.

WCF Supports Nine Types of Bindings

Basic Binding

Offered by the BasicHttpBinding class, this is designed to expose a WCF service as a legacy ASMX web service, so that old clients can work with new services. When used by the client, this binding enables new WCF clients to work with old ASMX services.

TCP Binding

Offered by the NetTcpBinding class, this uses TCP for cross-machine communication on the intranet. It supports a variety of features, including reliability, transactions, and security, and is optimized for WCF-to-WCF communication. As a result, it requires both the client and the service to use WCF.

Peer Network Binding

Offered by the NetPeerTcpBinding class, this uses peer networking as a transport. The peer network-enabled client and services all subscribe to the same grid and broadcast messages to it.

IPC Binding

Offered by the NetNamedPipeBinding class, this uses named pipes as a transport for same-machine communication. It is the most secure binding since it cannot accept calls from outside the machine and it supports a variety of features similar to the TCP binding.

Web Service (WS) Binding

Offered by the WSHttpBinding class, this uses HTTP or HTTPS for transport, and is designed to offer a variety of features such as reliability, transactions, and security over the Internet.

Federated WS Binding

Offered by the WSFederationHttpBinding class, this is a specialization of the WS binding, offering support for federated security.

Duplex WS Binding

Offered by the WSDualHttpBinding class, this is similar to the WS binding except it also supports bidirectional communication from the service to the client.

MSMQ Binding

Offered by the NetMsmqBinding class, this uses MSMQ for transport and is designed to offer support for disconnected queued calls.

MSMQ Integration Binding

Offered by the MsmqIntegrationBinding class, this converts WCF messages to and from MSMQ messages, and is designed to interoperate with legacy MSMQ clients.

Choosing Binding Type

C-Contract(What?): Specifies the interface between client and the server. It's a simple interface with some attribute.

Types of Contracts

What are Various Ways of Hosting WCF Services?

There are three major ways of hosting a WCF services:

Self-hosting the service in its own application domain. The service comes into existence when you create the object of Service Host class and the service closes when you call the Close of the Service Host class.

Host in application domain or process provided by IIS Server.

Host in application domain and process provided by WAS (Windows Activation Service) Server.

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About the Author

He is working On C#,Asp.net,window communication foundation(WCF),Silverlight from past 4+ years.He is flair for learning technology.He is active in programming communities and loves to share the knowledge with other developers whenever he gets the opportunity.

Hi Sachin,I read your WCF article it was just amazing and thanks for posting.I would like to ask you a few questions.I am using Telerik Reporting for Silverlight and it consumes a larger WCF service while rendering reports.So my TL gave a suggestion to make Reports use separate WCF service so I am trying to create a separate WCF service application project and integrated into my Solution. So now I have two hosting projects one for Reports and the other for my Application. Will it be possible to have 2 WCF service for a silverlight Application? If it is possible, how to access the WCF service that I have created for Reports? Will there be any Cross-domain access error? All your suggestions are welcome.

Hi,I want to publish the WCF application to intranet network. On the other hand, all subscribers connect to the service and this service connect to banking web service. So, which security model i choose?

Can you explain me what type application use WCF. We developed ERP PROJECT N-Tire architectural in EXISTING SYSTEM.Now we plan to move service oriented Architectural.how to pass the value code behind file to other service layers .We can possible dataset to service layer ..

Although I think the article misses out on pragmatic criticism and comparison of WCF-vs-other tech (ex raw socket... but then this is not what this article is about), I do appreciate the clear explanation and the diagrams. Thank you for the effort!

Perhaps somebody can tell me how much advantage you get by rolling your own RPC mechanism as supposed to WCF?How much time do you think it will take you to code up serialization,encryption,authentication-authorization,[de]compression... etc? And how much time you think you will need to spend on *learning* (memorizing) WCF config file switches and decipher svclog?

WCF is just beautiful. It just such cool technology I can't wait spend more time doing it!

This doesn't offer much over other basic WCF explanations. Furthermore a quick read shows that:1) You've repeated the sentence "In WCF, you have to just make different End points for different services. There is no need to learn a different API. You can use only one common API for communication with a different System." near the top. Ok, no big deal really but thought I'd mention. More importantly though....

2)Your graphic "Choosing binding type" has a decision point "WCF to WCF" existing twice which doesn't make sense. Then I remembered a similar, helpful figure in my "Programming WCF Services" book by Lowy and yep, sure enough, there it was on page 23, the exact same decision tree (minus the mistake - it should be "Cross Machine" instead). So, perhaps credit components of your articles where credit's due.

3) Your 2nd graphic....you really wouldn't want to host a WCF service in a Win Form application, receiving method calls from the internet like what is depicted there. It's just not practical.